Apparatus for heat treating articles



July 25, 1933. BLOUNT ET AL 1,919,821

APPARATUS FOR HEAT TREATING ARTICLES Filed Nov. 12, 1930 2 Sheets-Sheet 1 ATTORNEY Patented July 25, 1933 NITED STATES PATENT OFFICE HARRY BLOUN'I HAROLD SHEEL, OF BALTIMORE, MARYLAND, ASSIGNORS TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORA- 'IION or new YORK APPARATUS FOR HEAT TREATING ARTIGLE$ Application filed November 12, 1930. Serial No. 495,086.

This invention relates to an apparatus for heat treating articles and more particularly to an apparatus for continuously annealing spooled copper wire.

Objects of the invention are to provide an economical continuously operated appa ratus for annealing articles which will insure a product of high and uniform quality.

I11 accordance with features of the invens tion, these objects are accomplished by conveying series of spools of copper wire continuously through a water seal, a heatlng chamber, a soaking chamber and a cooling chamber, the walls of the chambers being designed to be closely adjacent the wire on the spools. Specifically one embodiment of the invention, by means of which the method may be practiced, consists of a vertical towor for annealing spooled wire wherein individual spools of wire are loaded upon the descending flight of a vertical continuously travelling endless conveyor. The conveyor carries them downwardly and transversely through a water seal and upwardly therefrom through a vertical heating chamber having a cross section slightly larger than the spools, transversely through a heated soaking chamber connecting the heating chamber with a steam sealed cooling chamber'lined with water filled cooling plates, and vertically downwardly through the cooling chamber to a discharge point slightly above the loading'point.

The invention will be more clearly understood by referring to the following detailed description read in connection with the accompanying drawings, forming a part thereof, in which Fig. 1 is a diagrammatic end elevation of a tower and conveyor constituting one embodiment of the invention.

Fig. 2 is .a diagrammatic side elevation of the structure shown in Fig. 1;

Fig. 3 is a plan View showing the mechanism for driving the conveyor shown in Figs. '1 and 2;

Fig. 4 is a section taken on the line l4: of Fig. 2 showing the cross sectional character of the structure shown in Fig. 2;

Fig. 5 is an enlarged view showing details of a typical cooling plate employed in the cooling chamber, and

V Fig. 6 is an enlarged section taken on the line 6-6 of Fig. 1 showing details of a bearing used for the lower sprockets.

Referring to the drawings, wherein like parts are indicated by identical reference numerals throughout the several views, a vertical continuously operating annealing furnace for spooled wire includes a tower generally designated by the numeral 10, having oppositely disposed ends l1-11 and sides 12-12which may be composed of sheet metalsecured uponany suitable rigid framework so as to form a substantially integral and air-tight jacket. The tower is secured by suitable angle braces 14, 14 positioned at each corner thereof to the floor or foundation 15. The foundation is excavated beneath the tower and the excavation is suitably lined to provide a water-tight tank 16 of a rectangular character to correspond with the cross section of the tower. The tank is normally filled with water, the water level therein being maintained at the level of an outlet 17 formed in the side of the tank for conducting any overflow-therefrom to a sewer or suitable receptacle 18. An inverted U-shaped pipe 70 extends to the bottom of the tank 16 and to any suitable external receptacle orpump (not shown) in order to provide means whereby the tank 16 may be completely drained.

A brick reinforced steel supporting wall 19 (Fig. 4:) extends across the tower from side to side, to form a vertical heating chamber 20 and a vertical cooling chamber 21. The heatingchamber is provided with a lining 22 of copper or other suitable corrosion resisting metal, the joints of which are welded or brazed so as to be air-tight,

and the space between the lining 22 and the tower walls is filled with heat resistant brick or other suitable insulating material. A skirt portion 23, secured to the copper lining, projects downwardly into thetank 16 and well below the water level therein in order to provide an air-excluding. seal for the heating chamber. The heating chamber is hexagonal in cross section (Fig. 4) to provide vertically extending fiat inner surfaces 24, 24, alon which are mounted a series of electrical heating elements 25, in number sufiicient to provide that a spool of wire introduced into the heating chamber at the bottom thereof and moved upwardly through the chamber in close proximity to the elements shall, when the top of the chamber has been reached, have attained the desired annealing temperature. The lining 22 is apertured at a number of spaced points to receive closely fitting electrical plugs 26, 26 of any suitable type for connecting the heating elements with any external current supply source (not shown), and a tubular conduit 27 is also provided through the lining 22 for receiving a closely fitting thermocouple fixture of any suitable type (not shown). A steam inlet pipe 28, supplied with superheated dry steam from any suitable source (not shown), extends into the heating chamber immediately above the water seal in order to assist in the exclusion of oxygen from the interior of the chamber. At the top the tower 10 is provided with a sealing dome or roof 29 which is connected with the sides and ends ofthe tower in an air-tight manner and lined with suitable heat resistant brick or other material. It will be noted, particularly in Fig. 2, that the heating chamber 20, wall 19 and cooling chamber 21 terminate a considerable distance from the top of the tower. The area. between the upper portions of these structures and the roof of the tower comprises a soaking chamber 30 which, being sealed at the top and in direct and free communication with the heating chamber, is normally maintained at the maximum desired annealing temperature by the heat rising from the heating chamber. By providing the soaking chamber and positioning it in the sealed dome 29 where the higner temperature is always maintained, the heating of those strands of wire on the interior of the spool to the desired annealing temperature while the spool is passed therethrough is obtained, thus insuring a uniform product. In order to assist in maintaining the temperature in the soaking chamber constant and discourage circulation and heat loss therein due to conviction or pressure, a baffle 31 extending from side to side of the tower is mounted therein. In order to permit the spools to pass through the soaking chamber during their movement from the heating chamber to the cooling chamber, the battle is provided with a lower central aperture 64 (Fig. 1).

The interior of the vertical cooling cham her is preferably rectangular and is lined with a number of hollow water-filled cooling plates 32 secured to the walls thereof, in number suflicient to warrant that an article entering the cooling chamber at the top thereof at the desired annealing temperature and moving slowly downwardly through the cooling chamber in a vertical line to the bottom thereof shall be cooled to a temperature sufiiciently low as to preclude all chance of deleterious oxidation. In order to maintain the temperature within the cooling chamber sufficiently low to accomplish this result, the cooling plates are arranged in horizontal tiers of four each, one plate of each tier being disposed on each of the internal faces of the cooling chamber, as shown in Fig. 4. Each plate is provided at the bottom with aninlet 33 (Fig. 5) for cold water, and at the top with an outlet 34, the former being connected to a cold water supply line 35, and the outlets 34 being connected to a pipe 36 which drains into the tank 16. In order to insure the exclusion of air from the cooling chamber, means for sealing it with steam is provided consisting of spaced inwardly projecting steam nozzles 37, 37 which are connected to a steam supply line 38. One of these nozzles is provided at the top of the cooling chamber, another in the center, and the third is located immediately above the lower end of the cooling chamber. The pressure of this steam throughout the cooling chamber will, due to the fact that the chamber is open to the surrounding atmosphere only at the bottom, be suflicient to exclude air from the en tirelength of the cooling chamber, and an article is therefore safe from oxidation as long as it is in the cooling chamber, or until it has been cooled below the oxidation temperature. Since a steady flow of cold water is maintained in the cooling plates at all times, prompt condensation of the steam takes place; the water of condensation dripping from the surface of the plates into the tank 16 and the cooling of the articles is achieved without wetting them, and a subsequent step of drying the articles after cooling is obviated.

A horizontal platform 39, mounted upon the tower at the top thereof by suitable braces 40, 40, supports a variable speed electrical motor 41 having a drive shaft 42. A speed reducing mechanism 43 is connected thereto for driving a main shaft 44, upon which is mounted a pair of sprockets 45. A pair of shafts 4646 journaled in suitable housings extend from opposite sides of the tower at the top thereof, each carrying a sprocket 47 which is driven by a chain 48 from one of the sprockets 45. A pair of larger sprockets 5050 are mounted on the shafts 46-46 on'the inner ends thereof and each carries an endless conveyor chain 51. The conveyor chains are provided with any desired number of hexagonal trays 52 upon each of which may be carried any article or articles to be annealed, such as a normally tightly coiled spool of wire. Embedded in the side walls of the tank at either side thereof and vertically alined with the shafts 4646 is a pair of stationary U-shaped guideways 54 (Figs. 1 and 6). A pair of grooved bearings 55, one of which is clearly shown in Fig. 6, for receiving opposite ends of a shaft 56 are slidably mounted on the respective guideways in order to permit the shaft 56 to be freely movable vertically. This shaft is provided adjacent each end with a pair of sprockets 57 which ride in the chains 51. By permitting the shaft 56 to move or float in the guideways 54, it will be apparent that the tension in the chains 48 will be kept uniform, and the possibility of one of the chains advancing beyond the other when operating with a consequent tipping of the trays 52 is obviated. A switch or control box 58, suitably connected to the motor 4:1 and any source of electrical energy (not shown), is mounted on the exterior of the tower within convenient reach of the operator.

At the bottom of the cooling chamber but above the tank 16 thetower is provided in the front end thereof with an aperture 59 by means of which access may be had to the trays and interior of the tower. A tiltable roller surfaced platform 60 is positioned adjacent the aperture 59 and adapted to be projected into the downward path of the spool for thepurpose of removing the spool from the trays 52 as the latter move downwardly past the platform. To facilitate this maneuver, the trays are centrally apertured at 61 to accommodate the platform. The tower 10 is provided at the top thereof with a vent or safety valve 62 for preventing the pressures within the tower from reaching danger proportions, and a central cabinet 63 is positioned at the end of the tower within convenient reach of the operator for regulating, in any suitable 'manner, the heating elements within the tower.

In utilizing the apparatus described above the tank 16 is filled With water to the level of the outlet 17 and the current is turned on in the heating chamber. When the temperature therein has reached the desired point, dry super-heated steam is caused to flow into the heating chamber and the cooling chamber, the water circulation through the cooling plates is established, and the motor 4-1 is driven to start the chain conveyor. Trays 52 thereon are thus moved downwardly through the cooling chamber, at the bottom portion of which a spool .of wire is loaded on the tray. The spool is then carried clownwardly and submerged in the water, being moved substantially transversely or horizontally of the tank 16 and remaining therein sufliciently long to insure that the spool is saturated or, in other words, until the water has penetrated to wet the inner strands of the spooled wire, removing all air from within the spool and insuring that none willbe carried into the heating chamber. This precaution being taken, and the heating cham her being sealed by the submerged skirt portion 23 of the heating chamber, asthe spool is moved upwardly through the heating chamber 20 its temperature is progressively increased without danger-of oxidation.

During its passage through the heating chamber, the temperature of the exterior strands of the coil is raised to the annealing temperature. In order to insure that the inner coils of the spool are heated to the annealing point of the wire, it is carried into the soaking chamber in which, since it is positioned above the heating chamber, is always maintained at atmosphere of annealing temperature. The spools are moved transversely or substantially horizontally across the soaking chamber and, passing through the baffie 31, are then carried downwardly through the cooling chamber. In so doing, they pass across the sealing jet from the upper steam nozzle. By maintaining a constant flow of cold water through the cooling plates, the atmosphere within the cooling chamber is maintained sufliciently low to re duce the spools during their passage therethrough from the annealing temperature to one considerably lower, or a temperature sufficiently low that oxidation will not take place when the coils are in the presence of oxygen. The trays pass the center and lower jets 37 and are lowered upon the unloading chute 62. The empty tray is then reloaded in any suitable manner and the steps are repeated with a fresh charge.

It will be observed from the foregoing that the structure for moving the articles through the annealing process gives a great economy in floor space and that since the operation is continuous, the furnace need not be closed down for recharging. Furthermore, an equalized temperature and a uniform anneal is imparted throughout the copper on the spool and discoloration and oxidation is prevented.

What is claimed is:

In an apparatus for treating articles, a liquid bath for saturating the articles, a vertical heating chamber for the articles, a soaking chamber connected thereto, a cooling chamber connected to the soaking chamber, an endless conveyor for continuously carrying the articles through said portions in succession, and means for driving the conveyor.

. HARRY BLOUNT.

HAROLD SHEEL. 

